1. Field of the Invention
The present invention relates to valves, and, in particular, to pressure-regulating valves.
2. Description of Related Art
Traditional pressure-regulating valves used in various pumps can sometimes experience instability, potentially resulting in pump and valve failure, for example instability due to contamination. Additionally, traditional valves can sometimes experience high droop, which can cause wear on the pumping elements. Droop is a term for the relationship between outlet pressure and flow rate. Flat droop indicates little to no change in outlet pressure as the flow rate increases and positive droop would indicate a gain in outlet pressure as the flow rate increases. Generally, the desired droop characteristic of the valve would be negative, meaning the valve sets a desired pressure for low-flow scenarios, and that pressure then reduces during high-flow scenarios, when other loads (e.g. centrifugal) are increasing on the pump. However, the traditional configuration used to achieve negative droop tends not to be prone to contamination. Maintenance is therefore required to alleviate the contamination. There are also scenarios in which flat or positive droop may be desired.
Such conventional methods and systems have generally been considered satisfactory for their intended purposes. However, there is still a need in the art for systems and methods that allow for improved regulating valves. The present invention provides a solution for these needs.